By default, the Checkout Bricks is instantiated/rendered with the default theme. However, it is possible to select another theme by setting the "theme" parameter when instantiating/rendering the Brick.

const bricks = mp.bricks({ theme: 'dark' });

If you set the theme on the instantiation of the Brick class, the theme change will be applied to all Bricks that can be instantiated. On the other hand, if the theme is set on render, changes to the theme will only be reflected in the Brick being created as the JavaScript shown below.

          
const settings = {
    ...,
    customization: {
        visual: {
            style: {
                theme: 'dark' | 'default' | 'bootstrap' | 'flat'
           }
        }
    }    
}

        

          
const customization = {
 visual: {
   style: {
     theme: 'dark' | 'default' | 'bootstrap' | 'flat'
   }
 }
};